/*
GanttProject is an opensource project management tool.
Copyright (C) 2005-2011 GanttProject Team

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 3
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/
package org.ganttproject.impex.htmlpdf;

import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import net.sourceforge.ganttproject.GPLogger;

import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;

public abstract class StylesheetFactoryImpl {
    public List<Stylesheet> createStylesheets(Class<? extends Stylesheet> stylesheetInterface) {
        IExtensionRegistry extensionRegistry = Platform.getExtensionRegistry();
        IConfigurationElement[] configElements = extensionRegistry
                .getConfigurationElementsFor(stylesheetInterface.getName());
        List<Stylesheet> result = new ArrayList<Stylesheet>();
        for (int i = 0; i < configElements.length; i++) {
            try {
                //Object nextExtension = configElements[i].createExecutableExtension("class");
                //assert nextExtension!=null && nextExtension instanceof HTMLStylesheet : "Extension="+nextExtension+" is expected to be instance of HTMLStylesheet";
                String localizedName = configElements[i].getAttribute("name");
                String pluginRelativeUrl = configElements[i].getAttribute("url");
                String namespace = configElements[i].getDeclaringExtension().getNamespaceIdentifier();
                URL stylesheetUrl = Platform.getBundle(namespace).getResource(pluginRelativeUrl);
                assert stylesheetUrl != null : "Failed to resolve url=" + pluginRelativeUrl;
                URL resolvedUrl = Platform.resolve(stylesheetUrl);
                assert resolvedUrl != null : "Failed to resolve URL=" + stylesheetUrl;
                result.add(newStylesheet(resolvedUrl, localizedName));
            }
            catch(Exception e) {
                if (!GPLogger.log(e)) {
                    e.printStackTrace(System.err);
                }
            }
        }
        return result;
    }

    protected abstract Stylesheet newStylesheet(URL url, String localizedName);
}
